Fitlet GPIO SDK for Linux

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Revision as of 13:06, 17 December 2015 by Irads (Talk | contribs)

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  • NOTE! Not supported in mainline Linux kernel. Linux Kernel for Fitlet should be installed to make this feature work
  • GPIO interface on fitlet consists of 9 GPIOs provided by AMD FCH (Fusion Controller Hub)
  • The responsible kernel module is gpio_fch
  • The kernel module uses the following pin naming convention:

GPIO connector pinout
Pin Number Color Code GPIO name Power domain HW source Notes
1 Brown GPIO89 3.3V SoC
2 Red GPIO132 3.3V SoC
3 Orange GPIO65 3.3V SoC
4 Yellow GPIO66 3.3V SoC
5 Green GPIO29 1.5V Soc
6 Blue I2C Clock 3.3V SoC
7 Purple I2C Data 3.3V SoC
8 Grey GPIO73 3.3V SoC
9 White GPIO27 1.5V SoC
10 Black GPIO28 1.5V SoC
11 Brown GPIO12 3.3V SoC
12 Red UART Rx 3.3V SuperIO
13 Orange UART Tx 3.3V SuperIO
14 Yellow GND

  • The GPIO sysfs interface allows users to manipulate any GPIO from userspace dynamically.
  • A basic example of GPIO P-1 (Brown) usage (as root user):
$ modprobe fch_gpio
$ echo 89 > /sys/class/gpio/export
$ echo out > /sys/class/gpio/gpio89/direction
$ echo 1 > /sys/class/gpio/gpio89/value
## at this point voltage measuring on P-1 (Brown) should give 3.3V
$ echo 0 > /sys/class/gpio/gpio89/value
## at this point voltage measuring on P-1 (Brown) should give 0.0V
$ echo 89 > /sys/class/gpio/unexport